Electronic payment has become widely used. Typically, an enterprise or individual issues a payment instruction to a financial institution such as a bank, directly or indirectly via an electronic terminal, to perform a cash payment and fund transfer. A common form of electronic payment is a payment at a point of sale terminal (e.g., the purchase of a product at a store), which requires both a bank card and a point of sale device networked with a bank for processing money transfer from the bank account of the buyer to that of the seller.
As mobile devices such as smart phones become more popular, more and more electronic payments are made through mobile terminals instead of using bank cards. This kind of payment is referred to mobile payment. The typical mobile payment system requires an intelligent chip to be added to a mobile phone or an existing SIM card to be modified, as well as a payment processing device to be installed at a point of sale. These requirements are often costly and complex to implement, thus hindering the wide adoption of mobile payment. Moreover, the security features of the typical mobile payment systems tend to be minimal or even nonexistent.